When applying lime, what matters is how much ENV (Effective Neutralising Value) you are applying with emphasis on the key word, Effective. This lime calculator is based on the NSW lime calculator that discounts for particle size. We know that lime must come in contact with acid for it to dissolve and raise the pH so the bigger the surface area of the lime, the better. Finer particles create a larger surface area and changes the pH faster.
The NSW lime calculator is based on sound science. Researchers in NSW, Scott and Conyers, took some crushed limestone (the typical liming product in NSW) and sieved it into its various particle size fractions. They then applied these different particle sizes to some plots, incorporated them to 10cm and monitored the pH change that followed. They then used this to determine the relative effectiveness of each different particle size and developed the NSW lime calculator. We believe this to be the most accurate lime calculator in Australia to allow us to compare between lime sources.
In the calculator we calculate equivalent rates of lime to achieve 1 t/ha of ENV. We are not recommending that this is the rate that everyone should apply, rather we are using this as a way to compare between lime sources.
We also advise that growers use a wet sieve analysis to determine particle size. Dry sieve has been favoured in WA for many years but this is not fair to all sources of lime. Some of the non-limesand lime sources clog the screens of a dry sieve and can be under valued. The wet sieve is the fairest way to allow us to compare apples with apples. Liquidlabs in WA offer a wet sieve plus NV of the various fractions for $150 per sample with a fast turnaround time on samples.
You can download your own copy of the MyResearchAgro lime calculator by clicking the button below and use your own numbers to work out the best option for you.